The Distribution of Growth-Phase American Eels in Saline Waters of the East Coast of North America

Despite intense conservation interest in the American eel (Anguilla rostrata), there exists no robust data source from which to assess population status across a broad spatial area in saline waters. Eel distribution in saline waters was evaluated by compiling eel count and presence/absence data from 25 saline surveys involving ca. 238,000 data points spanning 1959 to 2012. Eel captures were classified based on exposure to the sea as defined in a habitat atlas compiled by Cairns et al. (2012) that examined eel habitat compiled from eel fisheries data. Trends showed that the majority of eels occupy sheltered and semi-exposed saline waters; in particular, those waters of large bays and sounds in the USA. Canadian coastal surveys indicated a virtual absence of captures in open saline waters; however, US surveys had greater and variable numbers of eels. Mean depths and distance-to-land indicate that eels are most prevalent in shallow, near-shore waters. Trends and modeling, in their current state, provide compelling evidence of broad spatial and temporal habitat usage in saline environments primarily in sheltered coastal waters and semi-exposed bays. Data compilation and analyses presented here provide a methodology for investigating spatial and temporal habitat use patterns for other geographically widespread organisms.